split up crate using feature flags

Individual socket types are only implemented when they are requested via
the feature flag. Also, unless the `os-poll` feature is specified, the
crate is a shell.
12 files changed
tree: 52940cbcfcc13b89b2e6e44e96e1776290085502
  1. ci/
  2. examples/
  3. src/
  4. tests/
  5. .cirrus.yml
  6. .gitignore
  7. azure-pipelines.yml
  8. Cargo.toml
  11. README.md

Mio – Metal IO

Mio is a lightweight I/O library for Rust with a focus on adding as little overhead as possible over the OS abstractions.

Crates.io MIT licensed Build Status Build Status

API documentation

This is a low level library, if you are looking for something easier to get started with, see Tokio.


To use mio, first add this to your Cargo.toml:

mio = "0.6"

Then, add this to your crate root:

extern crate mio;


  • Non-blocking TCP, UDP
  • I/O event queue backed by epoll, kqueue, and IOCP
  • Zero allocations at runtime
  • Platform specific extensions


The following are specifically omitted from Mio and are left to the user or higher-level libraries.

  • File operations
  • Thread pools / multi-threaded event loop
  • Timers


Currently supported platforms:

  • Android
  • DragonFly BSD
  • FreeBSD
  • Linux
  • NetBSD
  • OpenBSD
  • Solaris
  • Windows
  • iOS
  • macOS

There are potentially others. If you find that Mio works on another platform, submit a PR to update the list!


A group of Mio users hang out on Gitter, this can be a good place to go for questions.


Interested in getting involved? We would love to help you! For simple bug fixes, just submit a PR with the fix and we can discuss the fix directly in the PR. If the fix is more complex, start with an issue.

If you want to propose an API change, create an issue to start a discussion with the community. Also, feel free to talk with us in Gitter.

Finally, be kind. We support the Rust Code of Conduct.